wilhelm gttlzow



(No Model.) I! W. GULZOW.

WATUH WINDING MECHANISM- Patented July 5, 1881.

Egg,

6 a 5 m W UNITED STATES PATENT OFFICE.

VVILHELM GULZOW, OF HAMBURG, GERMANY.

WATCH-WINDING MECHANISM.

SPECIFICATION forming part of Letters Patent No. 243,885, dated July 5, 1881.

Application filed May 23, 1881. (No model.) Patented in England December 29, 1879, in Germany January 1, 1880, in Belgium January 10, 1880, in France January 12, 1880, and in Austria June 14, 1880.

To all whom it may concern:

Be it known that I, W ILHELM GiiLzoW, of Hamburg, in the Empire of Germany, have invented certain new and useful Improvements 5 in Watch-Winding Mechanism, of which the following is a specification, and for which were granted British Letters Patent No. 5,307, dated December 29, 1879.v

My invention is applicable both to watchkeys and to stem-winding or keyless watches, and the object is to prevent the spring from being broken in case the person winding the watch continues to turn the key after the spring is entirely'wound up.

The invention consists in the combination, in a watch-key or watch with a key-head or winding-up button and abarrel or axle through which the turning of the head or button is transmitted to the watch-movement, of a screw connecting said head or button with said barrel or axle, and a spring which is compressed by said screw, and serves to lock the head or button to the barrel or axle by friction. The tension of this friction-spring is sufficiently strong to overcome the ordinary resistanceincurred in winding a watch; but when the mainspring is fully wound up the increased resistance is sufficient to overcome the friction of the aforesaid spring and causes the head or button to turn free of and without imparting any motion to the barrel or axle.

In the accompanying drawings, Figure 1 represents a side view, Fig. 2 a longitudinal section, and Fig. 3 an edge view, of a watch-key embodying my invention; and Fig. 4. represents a sectional view of the stem of a watch embodying my winding mechanism.

Similar letters of reference designate correspondin g parts in all the figures.

Referring first to Figs. 1, 2, and 3, A represents the barrel of a watch-key, and B designates the head thereof, here shown as ringshaped and made of a separate piece from the barrel.

design ates a screw, which is inserted loosely through the head B, and is screwed into the upper end of the barrel A; and a designates a small set-screw inserted in the barrel, and adapted to be set up to hold the screw (3 rigidly 50 in place after being adjusted.

Between the head of the screw 0 and the portion of the head below said screw-head is placed a flat spring, I), and the metal of the head B, immediately below the screw-head, is cutaway, so that by screwing down the screw 0 the spring I) is deflected downward and a tension applied thereto sufiicient to cause the barrel A and head B to turn together when the head Bis grasped in the fingers. So long as the mainspring ofa watch is being wound with this key the resistance offered by the mainspring is not sufficient to overcome the friction of the spring I); but as soon as the mainspring is fully wound up the resistance is so much increased that the friction of the spring I) is overcome, and the head B will turn without turning the barrel, and consequently without danger of breaking the mainspring by hard winding.

Referring now to Fig. 4, D designates the stem of a watch, and E designates the axle through which the winding is transmitted to the movement. This axle is rigidly fixed in a plug or core which fits within the stem,and may be properly considered as a part of the axle.

F designates the ordinary winding-up button, and O designates a screw like that previously described, whereby the button F is secured upon the end of the axle E. In this example ofthe invention the spring I) is arranged 8o between the button F and the end of the axle E, and by turning up the screw 0' the spring is deflected and serves by its friction to lock the button F to the axle. As soon, however,

as the mainspring of the watch is fully wound up the resistance is sufficient to overcome the friction exerted by the spring I), and the button F will turn without imparting any mot-ion to the axle By my invention I prevent any possibility 0 of breaking the mainspring by carelessly turning upon a watch-key or the winding-up button of a stem-windin g watch after the spring is fully wound up.

What I claim as my invention, and desire to 5 secure by Letters Patent, is

1. The combination, in a Watch-key or watch with a key-head or winding-up button and a barrel or axle through which the turning of the head or button is transmitted to the watch- I00 barrel A, the screw C, and the spring I), all substantially as and for the purpose specified.

WILHELM GULZOW.

Witnesses A. SGHAPER, V. REINOKE. 

